This common variant is reported to reduce adenosine deaminase enzyme activity. It has been associated with an increased tendency for non-REM sleep -- more slow wave sleep, less nocturnal wakings, and a stronger negative impact of sleep deprivation. A role for this gene and variant was previously proposed for autism susceptibility, but this is controversial and was not replicated by later studies.

[PMID 24896148] The functional polymorphism rs73598374:G>A (p.Asp8Asn) of the ADA gene is associated with telomerase activity and leukocyte telomere length